I try to use Ghiradelli, but if I don't have it I've used Hershey's in a pinch. I always melt chocolate for my chocolate BC, I like the texture better than cocoa.

There is a good thread under this forum started by hawkette titled "results of my chocolate cake test" Lots of good advice and recipes for chocolate cake. I tried the SCW chocolate cake this week after reading that forum and we really loved the texture and flavor of it.